"Every member of the Covenant shall walk the path. None will be left behind when our Great Journey begins. That is the Prophets' age-old promise, and it shall be fulfilled!"

— The Prophet of Regret

The High Prophet of Regret, born Lod Mron,[1] was the youngest of the three San'ShyuumHigh Prophets who led the CovenantHigh Council during the Human-Covenant War. Rash, ambitious, immature, and naive compared to the other Hierarchs, Regret originally served as Vice Minister of Tranquility, where he worked frequently with Sangheili and had adopted some of their personal traits, such as a preoccupation with honor and personal arms.[3] In many ways, he can be characterised as a Prophet who thought like an Elite; a rare mindset for his species, and from the High Prophet of Truth's point of view, a dangerous one. Regret was intelligent and fiercely opposed humanity through the course of the war.[4] He expected his soldiers to obey him without question.[5]

During the 23rd Age of Doubt, 2524 by the UNSC Military Calendar, Regret held the post of Vice Minister of Tranquility. He was unique among the Prophets for his confrontational demeanor, a trait he gained from working with the Sangheili.[6] He informed the
Minister of Fortitude, Ord Casto about the existence of Harvest and what they believed to be a vast repository of Forerunner artifacts. Tranquility sent a Sangheili crew to search for survivors of the ship that discovered Harvest and, at Fortitude's recommendation, told the Sangheili to execute survivors if they were found with stolen artifacts.[7] After conspiring with Fortitude to gain these artifacts for their own use, he helped him by pretending to sympathize with those blacklisted from reproducing due to inbreeding, which included the Prophet of Restraint. After pretending to be the father of two children Restraint had unlawfully fathered, Tranquility blackmailed Restraint into stepping down from his position as High Prophet.[8]

Before their coup, the Prophets visited the PhilologistHod Rumnt, leader of the ascetic priests aboard the Forerunner Dreadnought and keeper of the Oracle, which was actually the long-dormant Mendicant Bias, an ancient AI that had not spoken to anyone for thousands of years.[9] When the Luminaries of Harvest were entered into its matrix, the Oracle reactivated and said the symbols had been misinterpreted: the symbol didn't mean "Reclamation", but "Reclaimer", who it called his makers. Fortitude concluded that the these Reclaimers, the planet's aliens, were living Forerunners who had been left behind when the others transcended. Tranquility refused to believe this and accused the Philologist of tampering with the Oracle. As it attempted to launch the Dreadnought from High Charity the Lekgolo worms inside the Dreadnought short-circuited it and stopped Mendicant Bias.[10] Fortitude, Tranquility, and the Philologist made the decision to disconnect the Oracle from the ship and decided to eradicate humanity before any of the Covenant learned that the most basic premise of their faith was false, and that "living gods" would probably replace the Prophets. As such, their ascension was made, taking the names of Truth, Regret and Mercy.[11]

Upon the onset of the Human-Covenant War, Regret formalized the Fleet of Glorious Interdiction; a Sangheili-led military force under his personal supervision,[12] and appointed ArbiterRipa 'Moramee as its leader, choosing him for his ruthlessness and undying loyalty.[5] Obsessed with the Forerunners and the prospect of activating the Halo Array, Regret dispatched 'Moramee on numerous missions throughout Covenant and human space to find the means to do this.[13]

At the Etran Harborage, in a Forerunner installation known as the Apex Site, Regret discussed with Ripa the state of the installation, and that the recently glassed human world Harvest had a Forerunner relic buried in the planet's northern polar region. Regret sent Ripa to go and recover the secrets the site held to hopefully get his key to the Apex Site.[14] However, the relic on Harvest proved to be some sort of Forerunner mapping device, and with UNSC forces closing in however, Regret ordered that the relic be destroyed to prevent the retrieved information from falling into human hands. Against his instincts, the Arbiter obeyed.[15] However, despite Covenant efforts, the site was not destroyed, allowing the humans to learn of the information Regret planned to use.

Regret and Ripa 'Moramee.

Later, at the Apex Site, Regret discussed with the Arbiter his plans to activate the Forerunner dreadnoughts located there. When he could not activate the artifact himself, he ordered the Arbiter to capture the human female, Ellen Anders, who they encountered at the "Ice Relic" and bring her to the Apex.[16] Later when the Arbiter returned with her, Regret was in disbelief, saying "you would hardly think them a threat." When they learned the humans were closing in on them Regret evacuated to High Charity.[17] However, Regret's plans to use the dormant ships were foiled when the crew of the UNSC Spirit of Fire induced the collapse of the Shield World's internal sun, destroying all the ships and the planet. The Arbiter was also killed by Sergeant John Forge during the battle, depriving Regret of his prized warrior.[18]

Several days later, Regret was still in the Charybdis system when the Prophet of Truth visited his cruiser. Truth revealed his plan to Regret and informed him that the Kig-Yar leader, Reth, was attempting to find the coordinates to Earth while creating a large Unggoy army. Truth informed Regret that the Jiralhanae crew aboard A Psalm Every Day had betrayed 'Vadamee and suggested that Regret should execute them to prevent the rest of High Charity finding out. Then, the Infinite Sacrifice left the system to follow the coordinates to the world where Reth was creating the Unggoy army.[23]

After the cruiser arrived in the 23 Librae system, the Hierarchs discovered that the human insurgent base, the Rubble had been destroyed in a battle, and unfortunately Reth and his army were killed. After the battle, 'Vadamee and Zhar were brought before Truth and Regret aboard the Infinite Sacrifice.[24] Upon being told that he was to be executed for his failures, Zhar drew his Type-1 energy sword with the intent to murder the Prophet of Truth. However, Thel anticipated Zhar's attack, decapitating his former friend with his energy sword. This left Regret heavily shaken. In return, 'Vadamee was granted command of a ship in a new Covenant fleet and was ordered never to speak of the events that had transpired.[25] After the incident, the two Hierarchs returned to High Charity and decided that they needed to be more careful of the Sangheili "for the good of the Covenant".[26]

In 2551, a small Covenant team found a Luminary on Meridian after a battle on the moon, and the Luminary was delivered to Regret. By late 2552, two Stewards assigned to decrypt the Luminary finally revealed its content to Regret: the locations of the Halo rings and the place where the rings were created: the Ark, along with the location of a device which would generate a slipspace portal to the Ark, where the Covenant believed they could begin their "Great Journey" by activating the Halo Array. When Regret asked where the Portal was located, the Stewards revealed it was on a planet called "Erde-Tyrene". Immediately after this revelation Regret, without informing the other Hierarchs, ordered all ships at his disposal (two assault carriers and thirteen battlecruisers) to go to Erde-Tyrene.[27] Unbeknownst to Regret, Erde-Tyrene was humanity's homeworld, Earth. While the Prophet of Truth knew of the human presence on Earth, he had kept it, along with his personal plans for the planet and the Covenant, a closely guarded secret.[28]

On his way to Earth, Regret was holographically present at the trial of the Sangheili Supreme CommanderThel 'Vadamee (later the new Arbiter) who was responsible for the loss of Installation 04. Regret helped condemn 'Vadamee and suggested Truth to "make an example" out of him.[29]

"Dear humanity, we Regret being alien bastards, we Regret coming to Earth, and we most definitely Regret that the Corps just blew up our raggedy ass fleet!"

— Sgt. Johnson to Miranda Keyes on Regret's message.

When Regret arrived near Earth on October 20, 2552, he quickly found himself greatly outnumbered by UNSC defenses. Instead of retreating, however, he sped towards the planet in religious fervor, sending forces to destroy the orbital defense platformsMalta, Athens, and Cairo so he could push through into the heart of Africa aboard his personal flagship, Solemn Penance.[28] Despite the Master Chief's actions, his ship made it to the ground and deployed the first full-scale invasion force by the Covenant on Earth.[30]

After landing in New Mombasa, Regret's forces searched the city for the Forerunner artifact, supported by Scarabs and many Phantom dropships. The humans, however, managed to rout Regret's forces in the city, and also destroyed the remainder of his fleet, but not before his forces found at least some of the information they had been looking for. As the UNSC forces approached his carrier, Regret's ship initiated a slipspace jump in the middle of New Mombasa to Installation 05: from Regret's point of view, his troops had achieved their objective. The force generated by the jump heavily damaged the city. The move was so surprising that only the In Amber Clad and a few other UNSC ships were able to follow the carrier through the slipspace rupture.[31][32] Not long after Regret had left, an additional fleet sent by the Prophet of Truth arrived at Earth and deployed forces in Mombasa to pick up where Regret had left off.[28]

Using data from the Luminary he had previously obtained at Meridian,[27] Regret's jump took Solemn Penance and In Amber Clad to Installation 05.

"I shall light this holy ring, release its cleansing flame, and burn a path into the divine beyond."

— Regret

Regret's carrier deployed ground and infantry forces onto the surface of Installation 05, and set up a presence around a temple in the middle of a lake, from which Regret began his religious sermons.[33] He transmitted an apology to the Prophet of Truth, indicating that he couldn't have known that the humans would be on Earth or in such force. Truth responded that only Prophet of Mercy had spared him from public condemnation. Nevertheless, High Charity and the Second Fleet of Homogeneous Clarity rushed to the new Halo, and a flight of Phantoms was deployed to retrieve the Hierarch.[34]

John-117 kills the Prophet of Regret.

In Amber Clad arrived in the system soon after and deployed ODST forces on Installation 05 along with SPARTAN-117 to locate and kill Regret. The operation was a success, with the Spartan breaking through Covenant defenses, killing Regret and his bodyguards. Soon afterward, Truth ordered the Phantoms to return to High Charity and an assault carrier to use its glassing beam to destroy the temple. The Spartan was nearly killed and Regret was left for dead[34]

Regret as part of the Gravemind.

Regret's body was flung into the depths of the large lake surrounding the temple and later discovered by the Gravemind nested underneath the installation. His body was assimilated and reanimated by the Gravemind, although unlike many other Flood victims, he seems to have retained his individual consciousness even after his body had been completely absorbed by the Flood. After the Arbiter and John-117 were captured by the Gravemind, Regret expressed annoyance with another captive of the Gravemind's, 2401 Penitent Tangent, and reacted to the presence of the Arbiter, warning him to forget any heretical suggestions made by the Monitors and the humans and to pursue the Great Journey. It was thanks to Regret that the Gravemind discovered the location of the gateway to the Ark.[35] What remained of Regret was destroyed with the Gravemind when the replacement for Installation 04 was prematurely fired by the Master Chief and Cortana at the conclusion of the Raid on Installation 08.

Regret has shown his reckless nature more than a few times. Being the youngest of the Hierarchs, he tends to act rashly without thinking; he adopted his aggressive and brash demeanor during his extensive service alongside the Sangheili in missionary and expeditionary affairs.[35]

His recklessness and failure to communicate with the other Prophets caused significant trouble for Thel 'Vadamee and the Prophet of Truth when he ordered his forces to deal with the humans at the Rubble and the Kig-Yar trading with them. Upon learning the location of the Ark, Regret sped to Earth with an insufficient, hastily assembled fleet without consulting with his fellow Hierarchs first. Even as he faced Earth's formidable defenses he persistently headed for what he thought was an easy way for unlocking the Ark. This foolish mistake eventually cost him his life on Delta Halo. Regret did apologize to the Prophets of Truth and Mercy for his reckless and failed attack on Earth, although he may have simply been trying to justify his actions to which Truth responded in kind claiming that it was only thanks to Mercy that Regret "be spared of a public display" of their contempt.

Regret was very fond of the Sangheili and showed compassion towards them.[3] He was not involved in the betrayal and massacre of the Sangheili as he died prior to the Great Schism.[36] Regret likely would have opposed it, as evident of Truth marking him as a moderate that needed to be eliminated, as well as a scapegoat to kickstart the Schism.

After his death by John-117 and assimilation into the Gravemind, Regret showed no remorse for his actions against humanity however, and continued to preach the Covenant dogma, though he may not have been fully aware of his condition.

The gravity throne allows Regret to teleport a short distance away. The most effective way to deal with the Prophet is to jump onto his gravity throne and beat him to death with melee attacks. Energy swords will not kill the Prophet, though they can reduce the number of melee hits required to kill him. Rockets and fuel rods are surprisingly ineffective against Regret. Although he will shout out and bleed when hit, the player must still board his throne and melee him to death.

In skirmish and multiplayer, the Prophet of Regret is a hero unit. He is armed with a plasma cannon which can be replaced by a gravity cannon, and the "Cleansing" ability, which calls down an energy projector beam from an orbiting vessel. Regret's gravity throne can also be upgraded with the ability to fly. He can also be escorted by two Protector Sentinels when the Ancestral Perversion upgrade is researched. The Prophet of Regret will be automatically deployed as soon as the player finishes their first Temple. If that Regret is killed the player can purchase another for 400 resources, but can only have one Regret at a time.

Regret's title is, like all Prophet Hierarchs, ironic, as he never showed any regret for his actions, even after his death and subsequent assimilation by the Flood. He did, however, apologize to the other Hierarchs for attacking Earth with insufficient numbers, although he may have actually been attempting to justify his actions.

If the player melees Regret's hologram in any level, the Master Chief will lunge towards the hologram, much like the Arbiter can lunge through the Heretic Leadersholo-drone. The lunge is more noticeable if the player uses an energy sword.

On holograms of Regret, if one stands on the holo-panel or crouch on it, it can be seen that Regret has real eyebrows, even though it is a hologram.